Jump to main content
Jump to site search

Issue 22, 2016
Previous Article Next Article

Legitimate intermediates of oxygen evolution on iridium oxide revealed by in situ electrochemical evanescent wave spectroscopy

Author affiliations

Abstract

Understanding how the four-electron oxidation of water to dioxygen proceeds in different materials is critical to the rational design of efficient catalysts towards artificial photosynthetic systems. Here, using in situ electrochemical evanescent wave spectroscopy under oxygen-evolving conditions, we report two intermediates of iridium oxide (IrOx), which is the most active and stable catalyst characterized to date in acidic medium. The observed potential dependence of the two intermediates indicated that they were associated with different surface sites, and intermediate scavenging experiments using H2O2 provided insight into their role during catalysis. Notably, an IrV species with an absorption maximum at 450 nm was found to mediate the initial two-electron oxidation of water. Inhibition of the IrV species by H2O2, combined with computational modeling, indicates that the accumulation and concurrent spin-state change of the IrV species is a prerequisite for efficient water oxidation by IrOx electrodes.

Graphical abstract: Legitimate intermediates of oxygen evolution on iridium oxide revealed by in situ electrochemical evanescent wave spectroscopy

Back to tab navigation

Supplementary files

Publication details

The article was received on 11 Apr 2016, accepted on 12 May 2016 and first published on 12 May 2016


Article type: Paper
DOI: 10.1039/C6CP02385A
Citation: Phys. Chem. Chem. Phys., 2016,18, 15199-15204
  •   Request permissions

    Legitimate intermediates of oxygen evolution on iridium oxide revealed by in situ electrochemical evanescent wave spectroscopy

    H. Ooka, Y. Wang, A. Yamaguchi, M. Hatakeyama, S. Nakamura, K. Hashimoto and R. Nakamura, Phys. Chem. Chem. Phys., 2016, 18, 15199
    DOI: 10.1039/C6CP02385A

Search articles by author

Spotlight

Advertisements